Elevator cars are guided in their movement through hoistways by guide rails which are mounted in the hoistways. Conventionally, there will be two sets of three guide rolls or wheels mounted on each side of the car, one set projecting laterally from each side of the floor thereof and another set projecting laterally from each side of the roof thereof. The guide rails, which are T-shaped rails, are positioned with their stems, or blades, extending toward the sides of the car. The three guide rolls on the sides and the face of the rail blades roll over the rails as the car moves up and down in the hoistway. Ordinarily the two side guide rails and their associated rollers are sufficient to provide a smooth and steady ride for the car. In certain instances, however, when the elevator cars are unusually deep, such as is the case with a car which has passenger doors on both ends of the car, the length of the car can cause the car to oscillate sideways about the two guide rails, especially when the car moves at high speeds in the hoistway. This oscillation, or fishtailing, is unpleasant to experience and can alarm passengers in the car.